In-111 pentetreotide. Superior imaging agent for gastrinomas

Serum gastrin in Zollinger-Ellison syndrome: I. Prospective study of fasting serum gastrin in 309 patients from the National Institutes of Health and comparison with 2229 cases from the literature

The assessment of fasting serum gastrin (FSG) is essential for the diagnosis and management of patients with the Zollinger-Ellison syndrome (ZES). Although many studies have analyzed FSG levels in patients with gastrinoma, limited information has resulted from these studies because of their small size, different methodologies, and lack of correlations of FSG levels with clinical, laboratory, or tumor features in ZES patients. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of 309 patients with ZES and compare our results with those of 2229 ZES patients in 513 small series and case reports in the literature. In the NIH and literature ZES patients, normal FSG values were uncommon (0.3%-3%), as were very high FSG levels >100-fold normal (4.9%-9%). Two-thirds of gastrinoma patients had FSG values <10-fold normal that overlap with gastrin levels seen in more common conditions, like Helicobacter pylori infection or antral G-cell hyperplasia/hyperfunction. In these patients, FSG levels are not diagnostic of ZES, and gastrin provocative tests are needed to establish the diagnosis. Most clinical variables (multiple endocrine neoplasia type 1 status, presence or absence of the most common symptoms, prior medical treatment) are not correlated with FSG levels, while a good correlation of FSG values was found with other clinical features (prior gastric surgery, diarrhea, duration from onset to diagnosis). Increasing basal acid output, but not maximal acid output correlated closely with increasing FSG. Numerous tumoral features correlated with the magnitude of FSG in our study, including tumor location (pancreatic > duodenal), primary size (larger > smaller) and extent (liver metastases > local disease). In conclusion, this detailed analysis of FSG in a large number of patients with ZES allowed us to identify important clinical guidelines that should contribute to improved diagnosis and management of patients with ZES.

[Scintigraphy with 111In-octreotide in a case of primary hepatic gastrinoma]

Gastrinomas are uncommon tumors which are difficult to locate. They are often located in the head of the pancreas. About two-thirds of them are malignant, their growth is slow and they usually metastasize in the liver. In about 25% of cases, the Zollinger-Ellison (Z-E) syndrome is included in the multiple endocrine neoplasm type 1 syndrome (MEN 1).A 14-year old male patient presenting an episode of abdominal perforation which required emergency surgery is reported. The abdominal ultrasonography, CT scan and magnetic resonance revealed a single lesion in the left liver lobe, suggesting metastasis. Significantly increased levels of serum gastrin suggested a diagnosis of Z-E syndrome. A study with 111In-octreotide was required to locate the primary tumor and evaluate its extent. The scintigraphy showed only one abnormal uptake focus in the left liver lobe. Post-surgery scintigraphy studies revealed the presence of metastatic adenopathies which were removed after a second surgery. No pathologic findings were observed in the last nuclear medicine study. The somatostatin receptor scintigraphy is the most sensitive method to locate primary gastrinomas and to assess the tumoral dissemination in patients with Z-E Syndrome.